Hacker News new | ask | show | jobs
by Retric 748 days ago
> What? Currently, electricity makes for 20% of our global consumption.

An apples to apples comparison gives very different numbers. A heat pump uses 1 kWh of heat to produce 3 kWh or more worth of heat. A furnace needs over 3 kWh worth of gas to produce just 3 kWh worth of heat.

An ICE engine is more extreme as extraction, transportation, refining, takes 1/3 of the energy in oil before you even out it in the gas tank. Net result under 20% of the energy in oil ends up being used at the end of the process.

> Batteries only work to store energy for a few days, not between seasons.

There’s no point in storing power between seasons, just add more generation. A seasonal battery storing 1 MWh gets used once a season. A solar panel only used in the winter is still useful for ~4h * ~90 days. But worst case a ~3kW of solar is equivalent to that 1 MWh battery at less than 1/100th the cost, and whisk generally redundant the rest of the year it’s still reducing outages.

1 comments

> An apples to apples comparison gives very different numbers.

I don't see the relation with apples. If you take electricity where it works well, then it works well. But the fact that it accounts for 20% of our energy consumption today means that it does not work well everywhere. Try planes or merchant boats, for fun.

And that's not even mentioning that on those 20%, a good part is coming from coal.

> There’s no point in storing power between seasons, just add more generation.

You're saying "just waste solar panels during the summer so that you have enough during the winter", right? I thought it was pretty clear that wasting energy was not a good idea for the future.

> I don’t see the relation with apples.

Replacing an ICE with a EV results in a drop in energy by your calculations even if they are doing the exact same trip. Thus showing your argument is based on nonsense.

When someone burns oil in a car you measure the energy before it’s burned and therefore before engine inefficiency. If you burn oil in an electrical generator you measuring energy after the engine inefficiency.

Thus the amount of useful energy IE what people want in electricity vs other sources is closer to 50/50 than 80/20.

> You're saying "just waste solar panels during the summer so that you have enough during the winter", right? I thought it was pretty clear that wasting energy was not a good idea for the future.

People build grid infrastructure for the worst case. Nobody complains when a natural gas power plant is only turned on for 12 hours a year because without it you get a blackout. Hell dams build spillways that can sit unused for decades, you still need them.

Thus no the panels aren’t wasted, they are doing exactly the job someone built that infrastructure for.

> Thus showing your argument is based on nonsense.

My argument is that there is a lot more than just cars in the world. Even if Americans may not understand the concept. It's easy to say "replace oil with electricity, look, I have this one example where it works well". Then try to scale that one example, and then start looking at the rest. Again... planes and merchant boats for instance.

Many boats are going electric. Home heating, industrial processes, trains, mining, etc the vast majority of energy use you can swap without issue.

Rockets and big boats can swap to hydrogen with minor issues. Really aircraft are the odd man out, but remove bio fuels from other applications and you can largely replace aviation fuel.

After we drop CO2 emissions by 99% using existing tech we'll have decades to hit 100%.

> the vast majority of energy use you can swap without issue.

Then you completely misunderstand the scale of the problem.

> Rockets and big boats can swap to hydrogen with minor issues.

Say they can if they have the hydrogen, then you have to produce a whole lot of hydrogen and transport it for them. Do you know how inefficient that is?

Because you make it work for one does not mean that you make it work for the whole world. Your reasoning seems very naive.

> After we drop CO2 emissions by 99% using existing tech we'll have decades to hit 100%.

Except that the only way we drop CO2 emissions by a lot is with a ton of sobriety.

> scale of the problem.

Saying we don’t have the infrastructure is meaningless when building infrastructure is part of my argument. The only question is if we have the technology, and yes we do.

For scale, 350 gigawatts of PV was installed in 2023 that’s enough to meet ~3% of the words 25,000 TWh annual electricity demand (after accounting for capacity factor) and the rate of PV installed per year has been accelerating. Battery manufacturing capacity is already at weeks of global electricity demand per year. Utilities haven’t been building grid scale energy storage because they don’t need it, but it’s ready when they want it.

Over the next 20+ years a great deal of current infrastructure will need to be replaced simply because of age. What replaces it could be very green without significant issue.